'''Irreducible complexity''' ('''IC''') is a [[pseudoscience|pseudoscientific]] argument that certain [[biological system]]s cannot [[evolution|evolve]] by successive small modifications to pre-existing functional systems through [[natural selection]]. It is also use to explain the problems in the [[origin of life]] models.<ref>[S. J. Mojzsis et al., “Evidence for Life on Earth before 3,800 Million Years Ago,” Nature 384 (1996), 55-59.</ref><ref>J. William Schopf, “Microfossils of the Early Archean Apex Chert: New Evidence of the Antiquity of Life,” Science 260 (1993), 640-46.</ref><ref>Ivan G. Draganic, “Oxygen and Oxidizing Free-Radicals in the Hydrosphere of Early Earth,” presentation at the 12th International Conference on the Origin of Life and the 9th meeting of the International Society for the Study of the Origin of Life, San Diego, Calif., 1999.</ref><ref>Robert Shapiro, “The Homopolymer Problem in the Origin of Life,” presentation at the 12th International Conference on the Origin of Life and the 9th meeting of the International Society for the Study of the Origin of Life, San Diego, Calif., 1999.</ref><ref>[http://rsif.royalsocietypublishing.org/content/10/79/20120869.full Sara Imari Walker and Paul C. W. Davies, “The Algorithmic Origins of Life,” Journal of the Royal Society Interface 10 (2013), doi: 10.1098/rsif.2012.0869.]</ref><ref>*{{cite book |last= Forrest |first= Barbara |author-link= Barbara Forrest |url= http://www.centerforinquiry.net/uploads/attachments/intelligent-design.pdf |format= PDF |title= Understanding the Intelligent Design Creationist Movement: Its True Nature and Goals. A Position Paper from the Center for Inquiry, Office of Public Policy |date= May 2007 |publisher= Center for Inquiry, Inc. |place= Washington, D.C. |accessdate= 2007-08-22 |ref= harv}}.
*{{cite book |last= Smith |first= Jonathan C. |title= Pseudoscience and Extraordinary Claims of the Paranormal: A Critical Thinker's Toolkit |page= 307 |isbn= 1-40518-122-2 |ref= harv}}
*{{cite book |last= Shermer |first= Michael |title= The Skeptic Encyclopedia of Pseudoscience |publisher= ABC-CLIO |___location= Santa Barbara |year= 2002 |isbn= 1-57607-653-9 |page= 450 |ref= harv}}
